Say, while we're on the topic, i was thinking of switching my nearly 3 year old male to medium rats, smalls are ok, but seem a little too easy as of late. So last week i went to grab a medium but it was HUGE! I was expecting the difference between small and med to be noticeable but not dramatic - this seemed like a pretty dramatic difference in size, no way my guy is ready for these behemoth mediums, anyone else have this experience or some insight??